Patent application title: SUSPENSION LINK

Abstract:

A suspension link assembly is provided. The link assembly includes a link
member having a head portion and a shank. The head portion has a concave
surface. The head portion further includes a convex surface. At least one
bushing is provided. The bushing has convex and concave surfaces for
respectively engaging the concave and convex surfaces of the head
portion. A tapered aperture extends through the head portion from the
convex surface to the concave surface.

Claims:

1. A suspension link assembly comprising:a link member having a shank
portion and a head portion, said head portion having an inwardly directed
surface and an aperture there through; andat least one bushing having at
least a surface to contact the inwardly directed surface of said head
portion and having an aperture therethrough.

2. An assembly as set forth in claim 1 wherein said aperture in said shank
portion is tapered.

3. An assembly as set forth in claim 1 wherein said inwardly directed
surface is a concave.

4. An assembly as set forth in claim 3 wherein said surface of said
bushing is convex.

5. An assembly as set forth in claim 1 wherein said inwardly directed
surface is generally frustoconical.

6. An assembly as set forth in claim 1 wherein said inwardly directed
surface is generally flat.

7. An assembly as set forth in claim 3 wherein said head portion further
comprises a convex surface.

8. An assembly as set forth in claim 7 wherein said bushing further
comprises at least one surface to contact the convex surface of said head
portion.

9. An assembly as set forth in claim 8 wherein said at least one surface
to contact the convex surface of said bushing is concave.

10. An assembly as set forth in claim 5 wherein said head portion further
comprises a second inwardly directed generally frustoconical surface.

11. A suspension link assembly comprising:a link member having a shank
portion and a head portion, said head portion having a concave surface, a
convex surface and an aperture extending between said concave surface and
said convex surface; andat least one bushing adapted to engage at least
one of said concave surface and said convex surface, said bushing having
an aperture therethrough.

12. An assembly as set forth in claim 11 wherein said bushing comprises a
convex surface adapted to engage said concave surface of said head
portion.

13. An assembly as set forth in claim 11 wherein said bushing comprises a
concave surface adapted to engage said convex surface of said head
portion.

14. An assembly as set forth in claim 11 further comprising a second
bushing, said at least one bushing comprising a convex surface adapted to
engage said concave surface at said head portion; said second bushing
comprising a concave surface adapted to engage said convex surface of
said head portion.

15. An assembly as set forth in claim 11 wherein said aperture in said
head portion is tapered.

16. A suspension link assembly comprising;a bushing having a generally
cylindrical body portion;a first end surface having a generally convex
portion;a second end surface having a generally concave portion; andan
aperture extending through said cylindrical body portion from said first
end surface to said second end surface.

17. An assembly as set forth in claim 16 wherein said first end surface
comprises a generally flat surface intermediate the convex portion.

18. An assembly as set forth in claim 16 wherein said second end surface
comprises a generally flat surface intermediate the concave portion.

[0003]Suspension sway bar systems are designed to absorb road shock and
variable dynamic loads which, if not controlled, lead to poor handling
and unsafe vehicle performance. Suspension components are subjected to
harsh environments such as moisture, salt, road debris and dirt, all of
which have detrimental effects on each of the individual components.
Currently, different designs are used to provide a stabilizer link. A
common design is a ball-type design which comprises a polished steel ball
surrounded by a steel liner. One such ball joint type component is shown
in U.S. Pat. No. 6,019,383.

[0004]This type of design is advantageous in that it provides rotatability
of the ball and angular movement of the throughbolt part. Such a design
has many deficiencies such as minimal preload on the steel ball,
steel-to-steel contact, along with no provision for lubrication as a
means to extend life, and poor sealing of internal parts by a seal or a
boot. Intrusion of foreign material causes rust and degradation of the
internal parts resulting in accelerated wear, noise and excessive
clearance which leads to reduced vehicle control and the need for a
complete replacement at substantial cost. It is, therefore, desirable to
provide a link having an alternative design that reduces the deficiencies
of the prior art designs.

SUMMARY OF THE INVENTION

[0005]According to an embodiment of the present invention, there is
provided a suspension link assembly. The suspension link assembly
comprises a link member having a shank portion and a head portion having
an inwardly directed surface. The head portion further has an aperture
therethrough. The link assembly further includes at least one bushing.
The bushing has least a surface to contact the inwardly directed surface
of the head portion.

[0006]According to another embodiment of the present invention, there is
provided a suspension link assembly. The suspension link assembly
comprises a link member having a shank portion and a head portion. The
head portion further has an inwardly directed concave surface, a convex
surface and an aperture extending between the concave surface and the
convex surface. The link assembly further includes at least one bushing
having an aperture therethrough and adapted to engage at least one of the
concave and convex surfaces.

[0007]According to another embodiment of the present invention, a
suspension link assembly is provided. The suspension link assembly
comprises a bushing having a generally cylindrical body portion. The
suspension link assembly further comprises a first end surface having a
generally convex portion, a second end surface having a generally concave
portion, and an aperture extending through said cylindrical body portion
from the first end surface to the second end surface.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]The present invention will become more fully understood from the
detailed description and the accompanying drawings, wherein:

[0009]FIG. 1 is an exploded perspective view of an exemplary suspension
link in accordance with one embodiment of the present invention;

[0010]FIG. 2 is an exploded perspective view of link of FIG. 1;

[0011]FIG. 3 is a side view showing various positions of the embodiment of
FIG. 1;

[0012]FIG. 4 is a cross-sectional view of one component of the embodiment
of FIG. 1;

[0013]FIG. 5 is a side view of one component the embodiment of FIG. 1:

[0014]FIG. 6 is a top view of an alternate embodiment of the link member;

[0015]FIG. 7 is a cross-sectional view of the embodiment of FIG. 6;

[0016]FIG. 8 is a top view of an alternate embodiment of the link member;
and

[0017]FIG. 9 is a side view of the embodiment of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018]As seen in FIGS. 1 and 2, a suspension link assembly is generally
shown at 10. The link assembly 10 is shown from different perspectives
(angles) in FIGS. 1 and 2. The suspension link assembly 10 comprises a
link member generally indicated at 11. The link member 11 may preferably
be made of metal and most preferably steel. The link member 11 may have a
shank portion generally indicated at 12. The shank portion 12 may include
a threaded segment 14. The threaded segment 14 is for connecting the link
assembly 10 with another component in the suspension system (not shown)
as is well-known. The shank portion 12 may take any suitable
configuration.

[0019]The link member 11 further includes a head portion generally
indicated at 16. The head portion 16 may be fixedly secured to the shank
portion 12 and, may preferably be integrally formed therewith. Thus, the
head portion 16 and shank portion 12 may be formed as one piece.
Alternatively, the head portion 16 and shank portion 12 may be formed
independently and secured together. The head portion has a generally
circular cross-section.

[0020]The head portion 16 may have an inwardly directed concave surface 18
(FIGS. 2 and 4). The concave surface 18 may form a portion of a sphere.
Specifically, the concave surface 18 approaches an inner segment of a
sphere. The concave surface 18 may be bounded by an annular lip 20. The
annular 20 extends outwardly from the concave surface 18.

[0021]The head portion 16 may further include a convex surface 22 (FIGS. 1
and 4). The convex surface 22 is opposite the concave surface 18. The
convex surface 22 may comprise a portion of a sphere. More specifically,
the convex surface approaches the external surface of a sphere.

[0022]The head portion 16 may further include an aperture 24 therethrough.
The aperture extends from the convex surface 22 through the head portion
16 and through the concave surface 18. As best seen in FIGS. 3 and 4, the
aperture 24 may taper inwardly from the convex surface 22 to the concave
surface 18 at angle a from line A. Line A is perpendicular to the
longitudinal axis of shaft 12. In one embodiment, the aperture 24 may be
tapered between about 1 degree and about 20 degrees and most preferably
about 11 degrees from the concave surface 18 to the convex surface 22 as
shown in FIG. 3. Notwithstanding the description of the foregoing
embodiment, it will be appreciated that any suitable angle a may be used,
that provides suitable clearance for the troughbolt angle. This tapering
of the aperture allows for angular movement of a throughbolt (not shown).
More specifically, a throughbolt (not shown) may extend through the
aperture 24. By having the angular aperture 24, the throughbolt is
allowed to be positioned in various angular positions relative to head
portion 16. Various angular positions are shown, for example, in FIG. 3.
The use of a tapering aperture 24 is beneficial in that it allows for use
of the link in connection with various suspension assemblies. Sway bar
link assemblies are used to make the connection from the sway bar to the
suspension often at angles which, when the link assembly 10 is secured,
can cause uneven compression on the link assembly 10. By utilizing an
aperture 24 that allows for relative angular movement of the throughbolt
(not shown), allows to compensate for suspension variations. It also
helps to align the sway bar to the suspension arm or other contact point
and minimize uneven compression of the suspension link assembly 10.

[0023]The suspension link assembly 10 further comprises at least one
bushing generally indicated at 26. The bushing 26 comprises a body
portion 28. The body portion 28 may have a generally circular
cross-section. The body portion 28 therefore has a generally cylindrical
shape. As best seen in FIGS. 1 and 5, the bushing has a convex surface 30
on one end of the body portion 28. The convex surface 30 has a generally
spherical portion 32 adjacent the peripheral edge of the body portion 28
and a generally flat portion 34. The generally flat portion 34 is
intermediate the annular spherical portion 32. The generally flat portion
34 provides a surface to receive the head of a throughbolt (not shown).

[0024]The body portion 28 may further include a concave surface 36 (FIGS.
2 and 5). The concave surface 36 is opposite the convex surface 30. The
concave surface 36 may include a generally spherical portion 38 about the
peripheral edge of the body portion 28 and a generally flat portion 40.
The generally flat portion 40 is intermediate the generally spherical
portion 38.

[0025]An aperture 42 may extend through the body portion 28 from the
convex surface 30 to the concave surface 36. The aperture 42 may
preferably be generally cylindrical. In the most preferred embodiment,
the aperture extends from the generally flat portion 34 of the convex
surface 30 through the body portion 28 to the generally flat portion 40
of the concave surface 36. The aperture 42 may receive a throughbolt (not
shown).

[0026]In one embodiment, as shown in FIGS. 1 and 2, the suspension link
assembly 10 may include one link member 11 and two bushings 26. One of
the bushings 26 is adapted to engage the convex surface 22 of the head
portion 16. One of the bushings 26 is adapted to engage the concave
surface 18 of the head portion 16. More specifically, the concave surface
36 of one bushing 26 is adapted to engage the convex surface 22 of the
head portion 16. Similarly, the convex surface 30 of one bushing 26 is
adapted to engage the concave surface 18 of the head portion 16. A
throughbolt may pass through the aperture 24 of the bushing 26, through
the aperture 24 of the head portion 16 and through the aperture 42 of the
other bushing 26. The throughbolt (not shown) is adapted to connect the
link assembly 10 with the vehicle suspension (not shown).

[0027]The convex surface 30 of the bushing 26 and more particularly, the
generally spherical portion 32 thereof may be adapted to approximate the
concave surface 18 of the head portion 16. Similarly, the concave surface
36 of the bushing 26 and more specifically, the generally spherical
portion 38 thereof, may be adapted to approximate the convex surface 22
of the head portion 16.

[0028]By utilizing generally matching or mating concave and convex
surfaces, the bushings 26 can move within the spherical concave and
convex segments of the head portion and become self-aligning when
installed. The use of the generally spherical concave 18 and convex 22
surfaces in the head portion allows for rotational movement through
approximately 360° of the link member 11 and the use of the
angular aperture 24 allows for angular alignment. This design
approximates that of a prior art style ball design. FIG. 3 shows the
bushings 26 in various angular positions relative to the link member 11.

[0029]While it is most preferred that two bushings 26 be used, in the
manner described above, it will be appreciated that in certain
applications, only one bushing 26 may be required. The bushing may
contact either the convex surface 22 or concave surface 18 of the head
portion 16, depending on the application. If the bushing 26 contacts the
convex surface 22 of the head portion 16, then it is arranged so the
concave surface 36 of the bushing 26 contacts the convex surface 22, in
the manner described above. Similarly, if the bushing 26 contacts the
concave surface 18 of the head portion 16, then it is arranged so the
convex surface 30 of the bushing 26 contact the concave surface 18.

[0030]The bushings 26 are preferably constructed having the same
dimensions so that they can either be used to contact the concave surface
18 or convex surface 22 of the head portion 16. Thus, the bushings 26 are
interchangeable. It will be appreciated, however, that the bushings 26
may be of different dimensions for certain applications.

[0031]The bushings 26 may be elastomeric. Specifically, the bushings may
comprise poured urethane. It will be appreciated that any suitable
material may be used for the bushing. Other polymeric or rubber materials
may be suitable. In some embodiments, such as those shown in the Figures,
it is preferred that the concave 36 and convex 30 surfaces of the bushing
be relatively smooth. In some embodiments it is preferred that the
bushings have a durometer of between about 45 and about 90 on the Shore A
scale. It will be appreciated that any suitable hardness may be used. The
durometer and size of the bushings 26 may be adjusted to optimize the
performance of the link assembly 10.

[0032]The bushings 26 may be continually preloaded by a throughbolt (not
shown) to absorb and dampen various suspension impact loads. Further, by
using an elastomeric bushing 26 adjacent a metal link member 11, the
design requires no lubrication and provides relatively quiet operation as
compared with previous ball type linkage assemblies. The constant preload
absorbs impact loads and minimizes any clearance between the bushings 26,
link member 11 and other suspension components to which the link assembly
10 may be secured. The bushings 26 may contact the other suspension
components (not shown) to which the link assembly 10 may be secured.

[0033]Using a simple throughbolt through the bushings 26 and the link
member 11 makes the link assembly 10 easily rebuildable by simply
removing the throughbolt and replacing the bushings 26. The throughbolt
(not shown) can then be reinserted to attach the link assembly 10 with
the vehicle suspension.

[0034]FIG. 6 is a top view of an alternate embodiment. As shown in FIG. 6,
a link member for use in a suspension link assembly is generally
indicated at 11'. The link member 11' may preferably be made of metal and
most preferably steel. The link member 11' may have a shank portion
generally indicated at 12'. The shank portion 12' may include a threaded
segment 14'. The threaded segment 14' is for connecting the link assembly
with another component in the suspension system (not shown) as is
well-known. The shank portion may take any suitable configuration.

[0035]The link member 11' further includes a head portion generally
indicated at 16'. The head portion 16' may be fixedly secured to the
shank portion 12' and, may preferably be integrally formed therewith.
Thus, the head portion 16' and shank portion 12' may be formed as one
piece. Alternatively, the head portion 16' and shank portion 12' may be
formed independently and secured together. The head portion 16' has a
generally circular cross-section.

[0036]The head portion 16' may have an inwardly directed surface 18' (FIG.
7). The inwardly surface 18' may form a portion of a cone. Specifically,
the inwardly directed surface 18' may be frustoconical. The inwardly
directed surface 18' may be bounded by an annular lip 20'.

[0037]The head portion 16' may also include a second inwardly directed
surface 19' opposite to the inwardly directed surface 18'. Second
inwardly directed surface 19' may form a portion of a cone. Specifically,
the second inwardly directed surface 19' may be generally frustoconical.
The second inwardly directed surface 19' may be bounded by an annular lip
21'. While the inwardly directed surfaces 18', 19' are shown to be
frustoconical, it will be appreciated that they can take any suitable
geometric configuration. Further, while two inwardly directed surfaces
18', 19' are shown on opposite sides of the link member 11', it will be
appreciated that only one inwardly directed surface 18' may be used. In
such a case, the opposite side of the link member 11' can take any
suitable geometric configuration.

[0038]The head portion 16' may further include an aperture 24' extending
from the inwardly directed surface 18'. The aperture 24' is for allowing
a throughbolt (not shown) to pass therethrough. The aperture 24' may
extend between the inwardly directed surface 18' and the second inwardly
directed surface 19'.

[0039]The walls of one or more of the surfaces 18', 19' are preferably
generally frustoconical and may allow for angular surface for movement of
a throughbolt, as described above. This allows a throughbolt to have
angular movement relative to the link member 11'. The alternate link
assembly, including link member 11' may include at least one bushing (not
shown in FIG. 7). The bushing may have contoured surfaces of the type
described above. Alternative to the concave and convex surfaces as
described above, the bushing, for any embodiment described herein, may
have frustoconical end surfaces adapted to engage the inwardly directed
surfaces 18' or 19'. Still further, the bushings, for any embodiment
described herein, may simply be cylindrical, with flat end surfaces as
opposed to the concave, convex or frurstoconical surfaces described
above. Similarly, the bushings may be generally cylindrical, having one
generally flat end surface and one contoured end surface. The body of the
bushing may also have a shape other than cylindrical. It will be
appreciated that the bushing, for any embodiment described herein, can
have any geometric configuration within the scope of the present
invention.

[0040]The link assembly 11' may include two bushings. One bushing can be
place on each side of the head portion 16' such that one bushing can
contact each of the inwardly directed surfaces 18', 19'.

[0041]The bushings may be elastomeric. Specifically, the bushings may
comprise poured urethane. It will be appreciated that any suitable
material may be used for the bushing. Other polymeric or rubber materials
may be suitable. In some embodiments it is preferred that the bushings
have a durometer of between about 45 and about 90 on the Shore A scale.
It will be appreciated that any suitable hardness may be used. The
durometer and size and shape of the bushings may be adjusted to optimize
the performance of the link assembly.

[0042]The bushings may be continually preloaded by a throughbolt (not
shown) to absorb and dampen various suspension impact loads. Further, by
using an elastomeric bushing adjacent a metal link member 11', the design
requires no lubrication and provides relatively quiet operation as
compared with previous ball type linkage assemblies. The constant preload
absorbs impact loads and minimized any clearance between the bushings,
link member 11' and other suspension components to which the link
assembly may be secured.

[0043]Using a simple throughbolt through the bushings and the link member
11' makes the link assembly easily rebuildable by simply removing the
throughbolt and replacing the bushings. The throughbolt (not shown) can
then be reinserted to attach the link assembly 10 with the vehicle
suspension.

[0044]FIG. 8 is a top view of an alternate embodiment. As shown in FIG. 8,
a link member for use in a suspension link assembly is generally
indicated at 11''. The link member 11'' may preferably be made of metal
and most preferably steel. The link member 11'' may have a shank portion
generally indicated at 12''. The shank portion 12'' may include a
threaded segment 14''. The threaded segment 14'' is for connecting the
link assembly with another component in the suspension system (not shown)
as is well-known. The shank portion 12'' may take any suitable
configuration.

[0045]The link member 11'' further includes a head portion generally
indicated at 16''. The head portion 16'' may be fixedly secured to the
shank portion 12'' and, may preferably be integrally formed therewith.
Thus, the head portion 16'' and shank portion 12'' may be formed as one
piece. Alternatively, the head portion 16'' and shank portion 12'' may be
formed independently and secured together. The head portion 16'' has a
generally circular cross-section.

[0046]The head portion 16'' may have an inwardly directed surface 18''
(FIG. 9). The inwardly surface 18'' may be generally flat. The inwardly
directed surface 18' may be bounded by an annular lip (not shown).

[0047]The head portion 16'' may also include a second inwardly directed
surface 19'' opposite to the inwardly directed surface 18''. Second
inwardly directed surface 19'' may also be generally flat. The second
inwardly directed surface 19'' may be bounded by an annular lip (not
shown). While the inwardly directed surfaces 18'', 19'' are shown to be
generally flat, it will be appreciated that they can take any suitable
geometric configuration. Further, while two inwardly directed surfaces
18'', 19'' are shown on opposite sides of the link member 11'', it will
be appreciated that only one inwardly directed surface 18'' may be used.
In such a case, the opposite side of the link member 11' can take any
suitable geometric configuration.

[0048]As described in connection with the embodiment shown in FIGS. 8 and
9, the inwardly directed surfaces 18'' and 19'' refer to the generally
flat surfaces on opposite sides of the head portion 16''. Each of these
surfaces 18'' and 19'' are shown to be tapered inwardly from the shank
portion 12''. It will be appreciated that these inwardly directed
surfaces 18'' and 19'' extend directly from the shank portion 12'' and
not be tapered therefrom. That is, the flat inwardly directed surfaces
18'' and 19'' may be a continuation of the shank portion 12'' without
being tapered therefrom.

[0049]The head portion 16'' may further include an aperture 24'' extending
from the inwardly directed surface 18''. The aperture 24'' is for
allowing a throughbolt (not shown) to pass therethrough. The aperture
24'' may extend between the inwardly directed surface 18'' and the second
inwardly directed surface 19''. The aperture 24'' is shown to be
generally cylindrical. However, it will be appreciated that the aperture
24'' may taper inwardly from one inwardly directed surface 18'' to the
opposite inwardly directed surface 19''

[0050]The alternate link assembly, including link member 11'' may include
at least one bushing (not shown). The bushing may have contoured surfaces
of the type described above. Alternative to the concave and convex end
surfaces as described above, the bushing may have frustoconical end
surfaces. Still further, the bushings may simply be cylindrical with flat
end surfaces as opposed to the concave, convex or frustoconical surfaces
described above. Similarly, the bushing may be generally cylindrical,
having one generally flat end surface and one contoured end surface. The
body of the bushing may also have a shape other than cylindrical. It will
be appreciated that both the body and ends of the bushing can have any
geometric configuration within the scope of the present invention.

[0051]The link assembly may include two bushings. One bushing can be place
on each side of the head portion 16'' such that one bushing can contact
each of the inwardly directed surfaces 18'', 19''.

[0052]The bushings may be elastomeric. Specifically, the bushings may
comprise poured urethane. It will be appreciated that any suitable
material may be used for the bushing. Other polymeric or rubber materials
may be suitable. In some embodiments it is preferred that the bushings
have a durometer of between about 45 and about 90 on the Shore A scale.
It will be appreciated that any suitable hardness may be used. The
durometer and size and shape of the bushings may be adjusted to optimize
the performance of the link assembly.

[0053]The bushings may be continually preloaded by a throughbolt (not
shown) to absorb and dampen various suspension impact loads. Further, by
using an elastomeric bushing adjacent a metal link member 11'', the
design requires no lubrication and provides relatively quiet operation as
compared with previous ball type linkage assemblies. The constant preload
absorbs impact loads and minimized any clearance between the bushings,
link member 11'' and other suspension components to which the link
assembly may be secured.

[0054]Using a simple throughbolt through the bushings and the link member
11'' makes the link assembly easily rebuildable by simply removing the
throughbolt and replacing the bushings. The throughbolt (not shown) can
then be reinserted to attach the link assembly with the vehicle
suspension

[0055]The link assembly having the various configurations as described
above may have application in a vehicle suspension system. One or more of
the link assemblies can be used in connection with various suspension
components. The link assembly may be attached to any vehicle component,
such as by way of non-limiting example, suspension components, the
vehicle frame or axles.

[0056]The foregoing description is considered illustrative only of the
principles of the invention. The terminology that is used is intended to
be in the nature of words of description rather than of limitation.
Furthermore, because numerous modifications and changes will readily
occur to those skilled in the art, it is not desired to limit the
invention to the exact construction and process shown as described above.
Accordingly, all suitable modifications and equivalents that may be
resorted to fall within the scope of the invention as defined by the
claims that follow.